BOOBY TRAPPED: LOW WATER STREAM CROSSINGS

Low water stream crossings (LWSC) are locations at streamy designed to allow water to occasionally flood over the road. Floods at these crossings can ensure motorist inconvenience andd even threaten lives when vehicles and their occupants are swept away in rapidly rising flood waters. Such dangers imply high risk of liability for agencies and officials. This article reviews three studies which provide badly needed criteria for selecting, locating, designing and signing LWSCs. An FHWA study suggests that LWSCs be used on roads with less than 5 vehicles a day and avoided on roads with more than 200 vehicles a day. Average annual flooding should not exceed twice a year while the possible danger too human life should be less than one death per billion persons crossing. Expected overflow depths should not exceed one foot on roads with 100 vehicles per day for the greatest flow occuring on the storm water shed over a two year period. Pavement height be limited to four feet above stream level. An Iowa State study published in TRB Record N995 provides design criteria for LWSC's once locations have been selected. A second Iowa State study found little uniformity in signing for rud crossings. The study suggests that accident and liability risk could be reduced if motorists were discouraged from crossing LWSCs when flooded. A regulatory sign with the message "Do Not Enter When Flooded", along with two advance advisors signs "Flood Area Ahead" and "Impassable During High Water" were offered as possibilities.

  • Availability:
  • Corporate Authors:

    TranSafety Incorporated

    2020 K Street, NW, Suite 350
    Washington, DC  United States  20006
  • Authors:
    • Anderson, R W G
  • Publication Date: 1985-6

Media Info

  • Pagination: p. 4-5
  • Serial:
    • TRANSAFETY REPORTER
    • Volume: 3
    • Issue Number: 6
    • Publisher: TranSafety, Incorporated
    • ISSN: 0884-612X

Subject/Index Terms

Filing Info

  • Accession Number: 00396378
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Feb 28 1986 12:00AM